Setting spanning tree timers – ATL Telecom R1-SW Ethernet Switch User Manual

Page 276

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R1-SW24L2B User’s Manual

13-18

Setting Spanning Tree Timers

BPDU contains spanning tree timers (hello, forward delay, and max-age timers) that affect the
performance of the entire spanning tree. By default, the following values are set to the timers:

y

Hello Timer : 2 seconds

y

Max age Timer : 20 seconds

y

Forward delay Timer : 15 seconds


You can set spanning tree timers for individual VLANs. To set spanning tree timers for a
specific VLAN, perform this task in Privileged mode:

Table 13-10 Setting spanning tree timers

Command

Task

configure terminal

1. Enter Global configuration mode.

stp hello-time

<value>

vlan id

<vlan-id>

2.

Set the STP hello time for a VLAN.

y <value>

: The STP hello time. The hello time is the interval

between the generation of configuration messages by the root
switch (1 ~ 10 seconds, default: 2 seconds)

y <vlan-id>

: VLAN ID (1 ~ 4094)

stp max-age

<value>

vlan id

<vlan-id>

3.

Sets the STP maximum aging time for a VLAN.

y <value>

: The STP maximum aging time. The maximum aging

time is the number of seconds a switch waits without receiving
spanning-tree configuration messages before attempting a
reconfiguration. (6 ~ 40 seconds, default: 20 seconds)

y <vlan-id>

: VLAN ID (1 ~ 4094)

stp forward-delay

<value> vlan id

<vlan-id>

4. Set the STP forward delay for a specific VLAN.

y <value>

: The STP forward time . The forward delay is the

number of seconds a port waits before changing from its
spanning-tree learning and listening states to the forwarding
state. (4 ~ 30 seconds, default: 15 seconds)

y <vlan-id>

: VLAN ID (1 ~ 4094)

end

5. Return to privileged mode.

show stp vlan

<vlan-id>

6. Verify the STP configuration change.

y <vlan-id>

: VLAN ID (1 ~ 4094)


The following example shows how to set STP hello timers to 5 seconds for a VLAN:

# configure terminal

(config)# stp hello-time 5 vlan id 2

(config)# end

# show stp vlan id 2

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